Space Shuttle Atlantis Heads Back to Launch Pad as Storm Weakens

CAPE
CANAVERAL,
Fla. - NASA's massive transport vehicle
hauling the Atlantis orbiter towards a storm shelter stopped in its tracks
Tuesday and once more headed back to its Florida launch pad in an unprecedented
move.

"We are
going back to the pad," NASA KSC spokesperson Bruce Buckingham said shortly before
3:00 p.m. EDT (1900 GMT). "We expect to be back there in about five
hours."

The
announcement came about five hours after top shuttle officials gave the word to
move Atlantis into reinforced shelter inside NASA's 52-story Vehicle Assembly
Building (VAB) - known as a rollback - to weather high winds from Tropical
Storm Ernesto. Ernesto was expected to pass within 15 nautical miles (27 miles)
of Atlantis' Pad 39B launch site sporting wind speeds in excess of 40 knots (46
miles per hour).

"It does not
make sense to fool with Mother Nature," said Wayne Hale, NASA's shuttle program
manager, in a Tuesday teleconference before Atlantis changed course. "You want
to do what is safe and we decided it would be most prudent to go back to the
barn and wait it out there."

But
Atlantis, which has been delayed from a planned Aug. 27 launch to the
International Space Station (ISS), was midway though its 4.2-mile trek to the
VAB when its crawler transport stopped, then slowly began reversing direction
on course for the launch pad.

"Note even
in Apollo did we do that," NASA spokesperson Bill Johnson said of Atlantis'
rollback reversal.

A NASA
press briefing to discuss Atlantis' return to the launch pad is slated to begin
here at KSC by 4:30 p.m. EDT (2030 GMT).

Earlier
today, Atlantis' STS-115 crew - commanded by veteran shuttle astronaut Brent
Jett - left KSC and returned to NASA's Johnson Space Center (JSC) in Houston,
Texas for additional training. But a JSC spokesperson told SPACE.com
that the six STS-115 astronauts had not been taken out of quarantine, in which
they have only limited access to family and friends to avoid sickness before
launch.

Atlantis
has been plagued by weather-related delays for its planned STS-115 space shot,
a mission to resume ISS construction by delivering new solar arrays and truss
segments to the ISS.

NASA's
window to launch Atlantis extends through Sept. 7, when the space agency has
said it would stand down to avoid launch and landing conflicts with ISS-bound
Russian Soyuz spacecraft next month. If the agency fails to launch Atlantis by
Sept. 7, the next firm opportunity to do so opens in late October.

Atlantis'
launch pad return was prompted by updated forecasts for Tropical Storm Ernesto,
which weakened as it entered the Florida Straits Tuesday morning.

"The storm
has weakened and we will not exceed our wind requirements," Buckingham said.

NASA launch
director Michael Leinbach said Monday that it would take at least eight days
"give or take", once Atlantis returns to the launch pad, to again prime
Atlantis for liftoff. That means the shuttle could make another launch attempt
within its current window, if things go NASA's way.

When NBC
reporter Jay Barbree asked Leinbach what he would do
if, in fact, shuttle officials were able to stop Atlantis' rollback mid-stride
and return to the launch pad, he answered with a mix of humor and cynicism.